A substantial number of graphic recording systems have been developed to provide computer controlled graphic recording upon a media. While the individual structures of such graphic recorders vary substantially, generally all include a media transport system in which the media is moved in a first direction while a moveable pen carriage is moved in a second direction relative to media motion. In most instances, the directions of media movement and pen carriage movement are orthogonal.
While many systems utilize a pen carriage supporting a single recording pen, the development of computer drive systems having increased capability has made possible the use of graphic recording systems employing a plurality of recording pens. Most commonly, these multiple pen systems provide multiple color selection.
Because recording pens wear and require replacement and because graphic recording system users often wish to change pens and pen types, graphic recording systems generally provide for interchange and replacement of the recording pens. In the most common system for securing the recording pen or pens to the pen carriage, one or more threaded supports are formed within the pen carriage and recording pens defining cooperating threaded portions are received within the threaded supports. Because the recording pens are subjected to substantial vibration and stress in their typical use, it is necessary to secure the recording pens within the pen carriage in a rigid dependable attachment. In systems utilizing the above-described threaded attachment for the recording pens, a problem often arises in determining the proper securing torque to be applied when mounting a pen to the pen carriage. In the event an excess torque is applied, the threads of the pen carriage or the pen may be damaged. Conversely, in the event insufficient torque is applied, the stresses and vibrations imposed upon the pen may cause it to loosen during use. To meet this problem, several graphic recording system manufacturers have provided elaborate locking systems to further secure the recording within the pen carriage.
While the prior art systems have exhibited some degrees of success in securely attaching replaceable recording pens to the pen carriage, they often make the task of changing recording pens more difficult and time consuming than it should be. In multi-pen systems having six to ten recording pens, the more lengthy interruption of operation required to change recording pens due to the intricacies of their mounting systems may be particularly objectionable.
There remains, therefore, a need in the art for an improved recording pen attachment system for quickly and easily replacing or interchanging one or more recording pens within the pen carriage of a graphic recording system.